The present invention relates generally to devices for use with bags containing foods, potting soil compositions and the like and, more particularly, to clamps useful for closing, and opening, such bags.
As stated in the parent application, modem polymer bags afford significant protection to their contents and are generally economical in use. As a result, they are used for a variety of products ranging from foods such as potato chips, in relatively small and light bags, to potting soil compositions that are sold in large and relatively heavy bags.
The bags are generally of polymer construction with polypropylene and polyethylene compositions being often favored. These compositions tend to produce a bag that is impervious to environmental conditions such as pests and moisture. However, the bags often have slippery surfaces. This surface characteristic challenges inventors of bag closure devices since an effective bag closure device should effectively reclose the polymer bag, in spite of the slippery nature of the bag surface. In view of the challenge the polymer bag presents, a suitable closure device should protect bag contents by providing effective sealing of the bag. Desirably, the device would be inexpensive to manufacture and constructed of readily available materials.
Some conventional bag closure devices utilize latching mechanisms to hole together opposing jaws and such devices tend to be cumbersome in use and, if the latch slips, ineffective in operation. Thus, the clamp should actively hold the bag, preferably without a latching device.
In many cases, polymer bags are intended for repetitive use wherein the bag is opened, some contents are removed, and the bag is reclosed. Generally, it is important that the bag be securely closed. In the case of foods such as potato chips, for example, after the bag has been opened and some chips removed, it is desirable to have a technique for closing the bag to preserve freshness of the product and to prevent ants or other pests from gaining access to the chips. Thus, it is desirable to have an effective, easily used polymer bag closing device.
When heavier polymer bags, containing potting soil, for example, are utilized, a sturdy bag closing device is required. Desirably, the closure device would be of a type that does not become dislodged easily. Conventional clamping devices sometimes fail this test because they concentrate gripping forces near the clamp center. Movement of the heavy bag results in slippage of the bag at the clamp edges with spillage of bag contents sometimes resulting. This is due, in part, to the weight of the bag which, together with a slippery texture, can cause the bag to tear free of the clamping device.
Several conventional devices have been used to close polymer bags. Such devices are utilized, not only for closing food containers but also as clamping devices for garments and the like. In general, these devices have some utility but can be complicated and at least in some cases, they tend to slip, especially when heavy bags, such as potting soil bags are involved.
Accordingly, there is a need for an efficient, low cost and effective device for sealing a modem polymer bag. Such a device could be adapted for small bags and large while affording a substantial amount of purchase against the slippery surface of the bag, even at the edges of the device.
From the foregoing it will be apparent that there is a need for a polymer bag closure device that is reliable, effective, mechanically simple, easy to use and low in cost. In addition to these characteristics, it would be highly desirable if such a device could have utility in opening polymer bags in an effective manner.
The above having been said, another aspect of polymer bags deserves consideration. These bags are notoriously difficult to open. This is due, in part, to the strength of the synthetic material and effective sealing of the bag during the bag packing process. The result is a bag that can cause substantial difficulty as a consumer attempts to open it. In some typical cases, the consumer attempts forcefully to separate sealed bag surfaces. All too frequently, this action causes a rupture of the bag seal, destruction of the bag itself, and unwanted broadcast of breakfast cereal throughout a kitchen.
Clearly a need exists for an effective polymer bag clamping device having the above described characteristics. Desirably, such a bag clamp would be useful also for opening such a bag, in a convenient manner.
According to the present invention, there is provided a clamp for closing a polymer bag, including a pair of opposed clamp members wherein said clamp members are movable between a closed and an opened condition, each one of said pair of clamp members having a long axis and an inner and an outer surface. A hinge attaches the pair of clamp members and biases the clamp members into a closed condition. In holding a bag in a closed condition, a blade disposed on the inner surface of one of the clamp members is urged by the hinge against and an opposed recessed anvil, disposed on the inner surface of the other clamp member. In addition, a plurality of ribs disposed parallel to the clamp member long axis and located on the inner surface of each one of said pair of clamp members aid in gripping the bag within the clamp by intercalation of the ribs of one clamp with those of the other clamp. During the bag opening process, the ribs stretch the bag material for effective cutting when the material is moved past the blade.
The present invention affords several advantages. The combination of gripping surfaces on the clamp members provides a capacity for effective and efficient gripping of a polymer bag. Importantly, the blade and opposed, recessed anvil cooperate with the clamp member ribs to aid in distributing gripping forces away from the center of the clamp. Thus, a more efficient clamping capability is provided.
In addition, the parallel, intercalating ribs, disposed on the inner surface of each clamp member, aid in stretching the bag material and thereby facilitate the action of the blade during the bag opening process. In a preferred embodiment of the invention, the clamp is simple in construction and is comprised of readily available plastic materials.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.